It appears corals made it through a number of ELEs and PETM, so they should make it through AETM.(but humans won't)

History of Reefs According to the United States Geological Survey, fossil records reveal corals as old as 500 million years. Cyanobacteria are the oldest known reef-building organisms and have been in existence for approximately 3.5 billion years. During the Mesozoic period between 65 and 245 million years ago, hard corals were prolific reef builders, but by the end of the era something occurred that caused numerous coral reefs to vanish. Other species of corals similar to those still in existence today dominated theTertiary era between 2 and 65 million years ago, according to Sea World.org.

_________________"With every decision, think seven generations ahead of the consequences of your actions" Ute rule of life.“We do not inherit the earth from our ancestors; we borrow it from our children”― Chief Seattle“Those Who Have the Privilege to Know Have the Duty to Act”…Albert Einstein

If the only problem was climate change I would agree that it would be unlikely that coral would become extinct, but coral is under considerable stress form a range of human activities which leads me to think that they will become extinct.

Here is a quick list of problems off the top of my head roughly in order of impact

1 Pollution particularly excess run off of fertilizers and chemicals from farming especially sugar cane.

2 Water turbidity from land clearing, coral needs clear water as they rely on photosynthesis.

3 Extreme weather events such as high intensity cyclones which are expected to become more frequent due to climate change.

4 Shipping damage both mechanical and oil pollution

5 proliferation of species such as the crown of thorns either as introduced species or due to excess nutrients.

6 Changing PH levels due to absorption of CO2 making the formation of coral impossible or much more difficult.

8 sea temperatures becoming to high in some areas possibly balanced in the long term by currently colder areas becoming available.

The fixation on CO2 may well be causing us to not consider the real culprit.

I would put something like the pesticides or other chemicals which are flooding the world with often highly unusual inputs. Artifical estrogen from the contraceptive pill????

We should take the large scale disapearance of coral seriously. The sea level has not gone up, it's not that. The sea temperature has not gone up, it's not that. There have not been significantly more storms. The bleaching of corals below 6 inches excludes UV as the culprit. We need to find out what it is.

The fixation on CO2 may well be causing us to not consider the real culprit.

I would put something like the pesticides or other chemicals which are flooding the world with often highly unusual inputs. Artifical estrogen from the contraceptive pill????

We should take the large scale disapearance of coral seriously. The sea level has not gone up, it's not that. The sea temperature has not gone up, it's not that. There have not been significantly more storms. The bleaching of corals below 6 inches excludes UV as the culprit. We need to find out what it is.

So the scientists who study coral who say local temperature change has caused significant bleaching are wrong and your unsupported claims are correct?

When corals are stressed by changes in conditions such as temperature, light, or nutrients, they expel the symbiotic algae living in their tissues, causing them to turn completely white

Warmer water temperatures can result in coral bleaching. When water is too warm, corals will expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white. This is called coral bleaching. When a coral bleaches, it is not dead. Corals can survive a bleaching event, but they are under more stress and are subject to mortality.

In 2005, the U.S. lost half of its coral reefs in the Caribbean in one year due to a massive bleaching event. The warm waters centered around the northern Antilles near the Virgin Islands and Puerto Rico expanded southward. Comparison of satellite data from the previous 20 years confirmed that thermal stress from the 2005 event was greater than the previous 20 years combined.

Not all bleaching events are due to warm water.

In January 2010, cold water temperatures in the Florida Keys caused a coral bleaching event that resulted in some coral death. Water temperatures dropped -6.7 degrees Celsius (20 degrees Fahrenheit) lower than the typical temperatures observed at this time of year. Researchers will evaluate if this cold-stress event will make corals more susceptible to disease in the same way that warmer waters impact corals.

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Metrological observations have shown an increase in total annual precipitation throughout the United States. Analysis of metrological data suggests this change in precipitation can be associated with an increase in extreme storm events.

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The bleaching of corals below 6 inches excludes UV as the culprit. We need to find out what it is.

In any particular location it is no great problem to identify the main causesIn the case of the great barrier reef it isExtreme weather events The crown of thorns star fishFertilizer and chemical run offTurbidity due to land clearingHigh water temperatures

In 2005, the U.S. lost half of its coral reefs in the Caribbean in one year due to a massive bleaching event. The warm waters centered around the northern Antilles near the Virgin Islands and Puerto Rico expanded southward. Comparison of satellite data from the previous 20 years confirmed that thermal stress from the 2005 event was greater than the previous 20 years combined.

Did they recover?

Is this seemingly catastrophic dieing off of coral normal/natural?

Atributing this to a sea level rise or to a global temperature rise which has yet to happen is silly and will result in not doing the science which will answer the question of what if anything we should be doing about it.

In 2005, the U.S. lost half of its coral reefs in the Caribbean in one year due to a massive bleaching event. The warm waters centered around the northern Antilles near the Virgin Islands and Puerto Rico expanded southward. Comparison of satellite data from the previous 20 years confirmed that thermal stress from the 2005 event was greater than the previous 20 years combined.

Did they recover?

Some have to a degree but overall there has been a steady decline.

Quote:

Is this seemingly catastrophic dieing off of coral normal/natural?

Not according to the records we have.

Quote:

Atributing this to a sea level rise or to a global temperature rise which has yet to happen is silly and will result in not doing the science which will answer the question of what if anything we should be doing about it.

Coral do not grow globally so the global average temperature means little. The increase in temperature in the regions in which coral grows is important, however. That increase has already been documented.

Sea surface temperatures have been steadily rising in tropical/subtropical waters; e.g. they rose by an average of 0.3oC between the 1950s and 1990. It is likely that reef-building corals are now 1–1.5oC closer to their upper thermal limits than they were 100 years ago, with the result that warmer than average years, arising as a result of natural variability, now push corals beyond their upper thermal thresholds. Sustained temperatures as little as about 1–2oC above the normal summer maximum are sufficient to stress corals, and cause them to bleach.

As to what we should be doing, ignoring these unfounded assumptions you present would be a good start. That way the real science is not diluted by misinformation.

_________________With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none” Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."Albert Einstein

not to discount all the problems stressing these animals but there is a hope that the "bleaching" (the loss of whatever photosynthetic microbe that normally coexists with coral - three kingdoms of lifeforms have "algae") is merely that these microbes have not adapted to the new conditions yet and may repopulate the coral animals quickly once the necessary genetic changes have happened.

not to discount all the problems stressing these animals but there is a hope that the "bleaching" (the loss of whatever photosynthetic microbe that normally coexists with coral - three kingdoms of lifeforms have "algae") is merely that these microbes have not adapted to the new conditions yet and may repopulate the coral animals quickly once the necessary genetic changes have happened.

Yes, we can hope there is time for such an adaptation, but it cannot be guaranteed to happen.

_________________With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none” Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."Albert Einstein